From: Philippe Gerum <rpm@xenomai.org>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: "Mauerer, Wolfgang" <wolfgang.mauerer@siemens.com>,
Xenomai <xenomai@xenomai.org>
Subject: Re: [Xenomai] [PATCH] Revert "ipipe: ipipe_request_irq(), ipipe_free_irq() are root-only services"
Date: Thu, 20 Sep 2012 13:06:38 +0200 [thread overview]
Message-ID: <505AF8BE.70800@xenomai.org> (raw)
In-Reply-To: <505AF687.9010002@siemens.com>
On 09/20/2012 12:57 PM, Jan Kiszka wrote:
> On 2012-09-20 12:56, Jan Kiszka wrote:
>> On 2012-09-20 12:49, Philippe Gerum wrote:
>>> On 09/20/2012 12:37 PM, Jan Kiszka wrote:
>>>> This reverts commit 073ff1e8045d0311b8cf390687c0ba3619681672.
>>>>
>>>> Both service are NOT just root-only services. E.g., rtdm_irq_request
>>>> requires by specification support also over non-Linux contexts.
>>>
>>> Nack. We can't run the enable code for MSIs over non-root, and
>>> that code typically follows the irq request. Besides, we want to mask
>>> the source upon irq free to handle the SMP case properly, which we could
>>> not do from non-root with MSIs.
>>>
>>> So either we have both request+enable and free usable over non-root, or
>>> there is no point.
>>
>> OK, I get the point with legacy MSI. Then we have two other bugs to solve:
>> - in I-pipe as it holds a hardened spin lock across enable/disable (of
>> MSIs)
Missed it. Where?
>> - in Xenomai 2.6 (at least, didn't check forge) as it calls with a
>> hardened spin lock held into ipipe_virtualize_irq
>
> Sorry, three bugs:
> - in the RTDM spec as it always allowed rtdm_irq_request over RT task
> contexts
>
Yes. This was likely designed when ->enable/disable() handlers would not
traverse a whole pile of hairy code highly dependent on the PCI
infrastructure like today. And on the ppc side, this is not getting any
prettier.
> Jan
>
--
Philippe.
next prev parent reply other threads:[~2012-09-20 11:06 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-20 10:37 [Xenomai] [PATCH] Revert "ipipe: ipipe_request_irq(), ipipe_free_irq() are root-only services" Jan Kiszka
2012-09-20 10:49 ` Philippe Gerum
2012-09-20 10:56 ` Jan Kiszka
2012-09-20 10:57 ` Jan Kiszka
2012-09-20 11:06 ` Philippe Gerum [this message]
2012-09-20 11:15 ` Jan Kiszka
2012-09-20 11:27 ` Jan Kiszka
2012-09-20 13:01 ` Gilles Chanteperdrix
2012-09-20 13:15 ` Jan Kiszka
2012-09-20 14:12 ` Gilles Chanteperdrix
2012-09-20 15:00 ` Jan Kiszka
2012-09-20 15:13 ` Gilles Chanteperdrix
2012-09-20 13:10 ` Philippe Gerum
2012-09-20 13:54 ` Jan Kiszka
2012-09-20 14:05 ` Philippe Gerum
2012-09-20 15:07 ` Jan Kiszka
2012-09-20 15:16 ` Philippe Gerum
2012-09-20 15:45 ` Jan Kiszka
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